Cycloaliphatic unsaturated ketones as odour- and taste-modifying agents

ABSTRACT

Process for the preparation of unsaturated cycloaliphatic ketones useful as perfuming and odourmodifying agents in the manufacture of perfumes and perfumed products, and as flavouring and taste-modifying agents in the aromatization of foodstuffs in general and imitation flavours for foodstuffs, beverages, animal feeds, pharmaceutical preparations and tobacco products. Compositions of matter relating to some of said unsaturated cycloaliphatic ketones which are new, and perfume- and flavouring compositions containing same.

States Patent [191 Rautenstrauch et a1.

[ CYCLOALIPHATHC UNSATIURATED IKETONES AS ODOUR- ANl) TASTE-MODIFYINGAGENTS [75] Inventors: Valentin Rautenstrauch, 3,

Grand-Lancy/Geneva; Ferdinand Naf, Geneva, both of Switzerland [73]Assignee: lFirmenich S.A., Geneva,

' Switzerland [22 Filed: Aug. 29, 1972 21 -Appl. No.: 284,467

[30] Foreign Application Priority Data Aug. 31, 1971 Switzerland12755/71 [52] US; 260/586 R, 99/2, 99/23, 99/28, 99/65, 99/76, 99/92,99/134,

E, 260/631 R [51] llnt. C1. C07c 49/48 [58] Field of Search....,..-260/586 R, 587

[56] References Cited UNITED STATES PATENTS 3,483,257 12/1969 Chretienet a1. 260/586 R X [451, Dec. 3, 1974 OTHER PUBLICATIONS Chem. Abstractsvol. 71, pg. 807981 (1969) Kovals et al.

Primary Examiner-Leon Zitver Assistant Examiner-Norman P. MorgensternAttorney, Agent, or Firm-Dean S. Edmonds 5 7 ABSTRACT Process for thepreparation of unsaturated cycloali- Compositions of matter relating tosome of said unsaturated cycloaliphatic ketones which are new, andperfumeand flavouring compositions containing same.

2 Claims, No Drawings CYCLOALIPHATIC UNSATURATEI) KE'IONES AS ODOUR- ANDTASTE-MODIFYING AGENTS SUMMARY OFTHE INVENTION The invention relates toa new process for the preparation of unsaturated cycloaliphatic ketoneshaving the formula containing an isolated double bond in position I ortwo conjugated double bonds inposition l and 3 of the ring, the doublebonds being represented by the dotted lines, and wherein thesubstituents R and R may be the same or different and each represents ahydrogen atom or a lower alkyl radical containing from I to 6 carbonatoms, which process comprises treating a diol of formula comprising asaturated or mono-unsaturated six membered ring, the double bond beingindicated by the dotted line, with an acidic dehydrating agent. I

The invention relates further to a compound of formula I caste-"651cm"Rs R4 CHOHCHnE IIn CH3 containing a'doubleor triple bond in the positionindicated by the dottedlines and wherein the substituents R and R may bethe same or different and each represents a lower alkyl radicalcontaining from I to 6 'carbon atoms, and the index n stands for zero orI, which process comprises subjecting'an ether of formula -crr,-o-otr,oa,, oa.,-om

wherein the; dotted lines and the symbols R", R" and n have the samemeaning as above, to arearrangement by the action ofa strong base andsubsequently ofa protic solvent.

The above mentioned compounds V possess interesting organolepticproperties and may be used as intermediates for the preparation of thecorresponding ketones [see Swiss Pat Nos. 521,099 and 509,399].

BACKGROUND OF THE INVENTION One of the main objects of the aromatizationof foodstuffs for instance is to restore the original quality and natureof the flavour, aroma and taste of a given foodstuff material. Veryoften in fact the organoleptic properties of foodstuffs particularlydiminish or are some, how modified in the course of the processes offreezing and storage, or during the modifications, such as cooking orbaking, to which the foodstuffs are subjected in order to yield anedible material.

In thepast the aromatization was mainly achieved by using materials ofnatural origin. Nowadays, however, synthetic chemical compounds are usedat an ever increasing rate. Said compounds possess the advantage ofbeing available very often in unlimited quantities and at prices lowerthan those of the natural materials. Moreover, due to the fact that theflavouring character of a natural material is the result of the overalleffect determined by the combination and interaction of each of itsconstituents, the effects achieved by said natural material are veryoften not as well reproducible as those obtained by the use of the puresynthetic compounds.-

In the field of perfumery the man in the art has to solve a similarproblem in attempting to reconstitute the olfactive notes of certainnatural essential oils or extracts. The perfumers creativity however iscontinually boosted by the finding of new synthetic compounds, theorganoleptic properties of 'which will en able him to introduceunprecedented olfactive characters or nuances into new phantasy perfumecompositions.

As a consequence, the problem that the chemical industry has to solve isto satisfy the increasing demand of organoleptically interestingchemicals in order to better suit the specific needs of flavourists andperfumers.

The process of the present invention provides a novel and technicallyoriginal solution to the problem set by the synthesis of unsaturatedcycl-oaliphatic ketones of formula I. These compounds have: beenprepared in the past by various synthetic methods which can be resumedas follows:

a. partial hydrogenation of the corresponding acetylenic derivatives{Swiss Pat. No. 498,795];

b. direct condensationof an organo-metallic derivative of propene with acyclogeranyl derivative [Swiss Pat. No. 503,684];

c. cyclization of a pseudo-ketone by means of acidic cyclization agents[Swiss Pat. No. 503,685 1;

d. dehydrogenation of a cyclohexenic ketone to afford the correspondingcyclohexadienic derivative [Swiss Pat. No. 505,773]. I

The above indicated methods have the disadvantage of r i. affording thedesired compounds only in poor yield and/or ii. using non easilyaccessible startingmaterials.

The process of thepresent invention does notoffer to said disadvantagesand. as a consequence. it can be conveniently exploited by the chemicalindustry.

PREFERRED EMBODIMENTS OF THE INVENTION As mentioned above, according tothe invention compounds of formula I are prepared by treating a diol offormula II with an acidic dehydrating agent. A class of suitable acidicdehydrating agents comprises mineral or organic protonic acids such asphosphoricacid, sulphuric acid, trifluoroacetic acid orp-toluenesulphonic acid or acidic diatomaceous earths or an acidiccation exchange resin. For practical and economic reasons sulphuric acidis preferred.

We have observed that in the presence of derivatives of certain metalssuch as, for instance, copper, nickel or mercury salts, the yield of thefinal product was improved. To this effect it is preferred to usemercuric acetate. I

The temperature at which the dehydrating reaction can be carried out mayvary within wide limits. However, it has been observed that in order toobtain good yields of final product a temperature comprised be tweenabout 40 and about 90C, preferably between 60 and 80C, was convenient.

The concentration of the acid used can also vary within wide limits. Inparticular it is preferred to use an acid as defined above in anaqueous-solution. If sulphuric acid is chosen as dehydrating agent, aconcentration comprised between about and 50 preferably 30 (parts byweight), in water is conveniently used.

The diols of formula [I used as starting materials in the process of thepresent invention can be pfepared according to a known method [cf e.g.:Pharm. Bull., 4, 85-88 (1956), as reported in Chem. Abstr., 5 l 5007d(1956)] which .method comprises treating a cycloaliphatic ketone of'formula III with the organo-metallic compound obtained by the reactionbetween' an acetylenic alcohol, namely but-.lyn-3-ol, and ahalogenomagnesium derivative under the conditions normally used forcarrying out a Grignard reaction.

The following reaction scheme shows the aforementioned mode ofpreparation:

According to a modification of the method described above theorgano-metallic compound is a lithium derivative obtained by thereaction between but- 1 -yn-3-o| and a strong lithium base such asn-butyl-lithium, methwherein R and R have the meaning indicated forformula I. The said compounds occur in the form of two diastereoisomersof formula llllll IVa These isomers can be separated by means of theseparation techniques usually employed to this end, e.g. by fractionaldistillation or preparative vapour phase chromatography. Compounds offormula IV can be separated from the other constituents of the reactionmix-- ture by using the same techniques, the said constituents being,however, mainly represented by compounds I.

Among the compounds whose preparation was made possible by theapplication of the process of the present invention there is 2methyl-l-[but-2-enoyll-cyclohexl-ene which is a new compound and possessesinteresting organoleptic properties.

Equally new are certain diol intermediates of formula II, namelyZ-methyl-l -hydroxy-l -[3-hydroxy-but- 1- ynyl]cyclohexane and2,6,6-trimethyl- 1 -hydroxyl 3-.

hydroxy-but-l-ynyl]-cyclohex-2-ene.

According to another process of the present invention the alcohols offormula V are prepared by subjecting an ether of formula VI to arearrangement by the action of a strong base and subsequently of aprotic solvent.

A suitable strong base is represented by an organometallic compoundwhich is dissolved or which is in suspension in an inert organicsolvent. Typically, there is used an alkyl-lithium such asn-butyl-lithium, hexyllithium or isopropyl-lithium, in an etherealsolvent such as ethyl ether, monoglyme, diglyme, dioxan ortetrahydrofuran, or a hydrocarbon such as cyclohexane, hex ane, benzeneor toluene.

/ Suitable protic solvents include an alcohol such as methanol,isopropanol or ethanol, or water.

The reaction between the ether of formula VI and the strong base can becarried out at a temperature comprised between about 90 and about +50C.However, it has been found that the best yields of final product areobtained if temperatures comprised between about -80 and 50C, preferablyof C, are used.

n-Butyl-lithium in ether or tetrahyd'rofuran is preferably used as thestrong base. The preferred protic solvent is water. I

Moreover, ether Vl is advantageously treated with n-butyl-lithium in thepresence of a catalyst, which cat alyst is destinedto increase the rateof the rearrangement. A class of suitable catalysts includes thosesubstances which are known to increase the efficacy of alkyl-lithiumreagents, such as tetramethylethylenediamine [cf. e.g. J. Org. Chem, 29,2928 (1964)] or potassium tert-butoxide [cf. eg. J. Organometallic Chem,8, 9 (1967)].

The alcohols of formula V, some of which are new, possess interestingorganoleptic properties and represent useful intermediates for organicsynthesis and are particularly interesting in the field of perfumes andflavours. Indeed, by subjecting them to an oxidation according totheusual techniques they lead to the ketones corresponding to formulagenation can be carried out in the presence of a catalyst of theso-called Lindlar type [deactivated Pd/C catalyst, see Helv. Chim. Acta,35, 446 (1952)].

By the above described method there are obtained compounds Vllbin theform of a mixture comprising the cisand trans-isomers in a ratio byweight of about 4 l. The said isomers can be purified by the usualtechniques of separation such as preparative vapour phase chromatographyor fractional distillation.

The partial reduction of the acetylenic triple bond of compounds V bymeans of reagents such as mixed lithium and aluminum hydride, however,leads almost exclusively to the formation of compounds having atransconfigu'ration.

Thus, e.g., if 2-methylene-6,6-dimethyl-'l-[1-hydroxy-but-Z-ynyl]-cyclohexane is reduced by means of LiAll-ltrans-2-methylene-6,6-dimethyl-l-[ lhydroxy-but-2-enyll-cyclohexane isobtained.

. The ethers of formula Vlgused as starting materials in the process ofthe invention described above, can be obtained by treating alcoholshaving the formula .VIII

According to a modification of the synthetic method indicated above, analcohol having the formula CH -CH,, E CH,,CH OH containing a double ortriple bond in the position indicated by the dotted lines and wherein nstands for zero or I, is treated with a basic lithium reagent of thetype mentioned above, and the resulting product is then eth erified bymeans of a halide having the formula wherein X represents a halogen suchas chlorine or bromine.

Among the compounds whose preparation was made possible by theapplication of the processes of the present invention there are thecompounds of formula a. containing an exocyclic double bond inposition 2of thering and a triple bond in position 2', and wherein Y represents anoxygen atom or an OH group and a hydrogen atom, each of the substituentsR represents a lower alkyl radical containing from l to 6 carbon atomsand n stands for zero; or

b. containing a double bond in position 1 of the ring and a double bondin position 2', and wherein Y represents an oxygen atom, each of thesubstituents R represents a hydrogen atom and n stands for 1.

Specific examples of the compounds of formula Xl include2-methylene-6,6-dimethyll l-hydroxy-but-Z- ynyl]-cyclohexane,2methylene-6,6-dimethyl-l-[but- 2-yn0yl]-cyclohexane andZ-methyl-l-[but-2-enoyl1- cyclohex-l-ene which are new compounds andpossess interesting organoleptic properties.

We have surprisinglyfound that the above mentioned cycloaliphaticderivatives possess distinct olfactive and flavouring characters and maydevelop a variety of notes such as the fruity, spicy, leathery notes.They improve the lifting character of the compositions to which they areadded and confer freshness to the resulting overall effect achieved bysaid compositions.

The above mentioned compounds can therefore be used as perfuming andodour-modifying agents in the manufacture of perfumes and perfumedproducts, and as flavouring and taste-modifying agents for thepreparation of artificial flavour compositions and for the aromatizationof foodstuffs, animal feeds, beverages, pharmaceutical preparations andtobacco products.

In some cases, they impart to the products, in which they areincorporated, a taste of 'red berries and can be used for improving thetaste and the artificial flavour of strawberry, cranberry, cherry,red-currants or analogous compositions. They may equally develop afruity taste reminiscent of peach, apricot or even melon. ln

7 particular, 2-methyl-l-[but-2-enoyl1-cyclohex-l-ene confers to thefruit base compositions to which it is added a character of dried fruitwhich may be especially desired by the foodstuff industry in general andby the confectionary in particular.

The proportions in which the new compounds can be used in order toproduce an interesting odoriferous effect vary within wide limits. Inthe preparation of perfume compositions, for example, interestingeffects can be obtained by the presence of the new compounds in ratiosof about 100 ppm to 5 of the total of the composition. Depending on thedesired odoriferous effects the ratios of these new compounds can. beincreased to about and even more.

If the new compounds are used as flavouring agents or as additivesdestined to modify the organoleptic properties of foodstuffs for men andanimals, beverages, pharmaceutical preparations and tobacco, theirratios can also vary within wide limits.

Interesting flavouring effects can e.g. be obtained by the use of 0.1 to10 ppm of the new compounds, based on the product to be flavoured.However, these ratios can be increased beyond '10 ppm and reach 100 ppmif it is desired to obtain special flavouring effects. In thepreparation of flavouring compositions by admixture of the new compoundswith other flavouring agents the said compounds can be used in ratios ofabout 0.1 to of the total of the composition. In many cases the averageof the ratios usedliesbetween I and 10 of the total weight of thecomposition. It is to be understood that the limits of the proportionsgiven above do not represent absolute limits; in certain cases wherespecial effects are desired the new compounds can be used in higher orlower concentrations than those mentioned above.

The expression foodstuff is used in this specification in its broadestsense. It also comprises products such as coffee, tea and chocolate.

The invention is illustrated in a more detailed manner by the followingexamples, wherein the temperatures are indicated in degrees centigrade.

EXAMPLE 1 Z-lVlethyl-1-[but-2-enoy1]-cyc1ohexl-ene g of 50 aqueoussulphuric acid (parts by weight) were added to 20.2 g (0.1 I mole) of2-methy1- l-hydroxy-1-[3-hydroxy-but-l-ynyl]cyclohexane and the thusobtained mixture was stirred for 45 minutes at 50. After having addedwater to the said mixture, it was extracted three times with pentane,and the com bined organic extracts were washed, dried (MgSO andconcentrated. The resulting residue gave, by fractional distillation, aproduct of hp. 1 18-120/12 Torr; 10.9 g (60 %)..By purification by meansof vapour phase chromatography there was'obtained Z-methyl-l-[but-2-enoyl ]-cyclohex- 1 -ene.

IR 2920, 2850, 1710, 1660, 1435, 1370, 1280, 1250, 970 cm NMR 1.6 (m);1.84 (q, J,=1 cps, J =6.5 cps); 2.0

'(m); 5.83 (m); 6.09'(m); 6.30-6.80 (m) 6 ppm MS: 164, 149,135,121, 67,55, 44, 41. y 2-Methyl-1-hydroxy-1-[3-hydroxy-but-1-ynyl]- cyclohexaneused as starting material in the hereinabove preparation can be obtainedas follows:

A mixture of 20.0 g of methylcyclohexanone (0.20 mole) and 19.3 g ofbut-1-yn-3-ol (0.28 mole) was added dropwise within 45 minutes to asuspension maintained at +5 of 20.0 g of potassium tert-butoxide (0.18mole) in 100 ml of anhydrous ether, and the resulting reaction mixturewas maintained at room temperature overnight. After the addition ofwater, the ethereal phase was separated and the aqueous phase was twiceextracted with pentane. The combined organic extracts were washed withwater, dried (MgSOq), and the volatile portions were evaporated to yielda residue which, by distillation, gave 25.5 g 7r) of the desired diol;b.p. -94/0.02 Torr.

NMR 1.04 (m); 1.2-2.0 (m); 4.2-4.8 (m) 5 ppm EXAMPLE 22,6,6-Trimethyl-1-[but-2-enoyl]-cyclohex-l-ene A mixture of 6.6 g of 30aqueous sulphuric acid (parts by weight) and 6.6 g of 2,6,6-trimethyl-1-hydroxy-1-[3hydr0xy-but-1ynyl]-cyc1ohexane (32 millimoles) was stirredfor 24 hours at 70. After the addition of water, the reaction mixturewas extracted 3 times with ether and the combined organic extracts werewashed with water and sodium bicarbonate, dried and concentrated. Theresulting residue was distilled to yield 5.4 g of a product of hp.114-117/l2 Torr (yield: 90 The distillate by preparative vapour phasechromatography yielded two products. The first one was the desiredproduct whose analytical data were identical with those of a pure sample[cf. French Pat. No. 1,591,031]. The second one was a mixture ofdiastereoisomers of theaspirene.

IR 2840-2990, 1470, 1450, 1380, 1370, 1350. 1115, 1080, 1060, 1000, 980,910, 870, 860 810, 750, 710 cm" NMR 0.96 (d); 1.23 (d); 1.16 (m);1.70-2.20 (m); 4.83 (q, broad band); 5.1-5.9 (m) 8 ppm MS: 192,136,121,93,77, 53, 43, 41, 39.2,6,6-Trimethyl-1-hydroxy-1-[3-hydroxy-but-1-ynyl]- cyclohexane used asstarting material in the above described preparation can be synthesizedas follows:

a. 1 10 ml ofa solution of 30 H 0 followed by 28 ml of a 6N aqueoussolution of NaOH were added dropwise, while stirring and within 45minutes and 15 minutes, respectively, to a cooled solution (0-5) of 40 gof B-cyclocitral (0.26 mole) in 300 ml of methanol which had beenacidified beforehand with 40 drops of concentrated sulphuric acid. Thereaction mixture was then kept at room temperature for 3 days, whilestirring, After having added water thereto, the said mixture wasextracted 3 times with ether and the combined organic extracts weresubjected to the usual treatments of washing (water), drying (MgSO andconcentration. There -were obtained 21.5 g of trimethyl-cyclohexanone byfractional distillation; b.p. 66-69/12 Torr (66%).

b. m1 of a 1.65 N solution of n-butyl-lithium in hexane (0.21 mole) wereadded dropwise within 20 minutes to a solution, kept at 75, of 7.5 g ofbut- 1-yn-3-ol (0.1 mole in 50 ml of tetrahydrofuran. The reactionmixture was then kept at room temperature for 30 minutes, then againcooled to -75". At this temperature there were rapidly added 10 g oftrimethyl-cyclohexanone 70 millimoles) disband) 6 ppm EXAMPLE 32,6,6-Trimethyl-1-[but-2-enoy11-cyc1ohexa-1,3-diene A mixture of 0.200 gof 2,6,6-trimethyl1-hydroxy-1- [3-hydroxy-but-1-ynyl]-cyclohex-2-ene,0.2 ml of 5 aqueous sulphuric acid (parts by weight) and 0.050 g ofmercuric acetate was heated at 50 during 22 h. After cooling, thereaction mixture was poured onto 5 ml of water and then extractedseveral times with ether.

The combined organic extracts were subjected to the usual treatments ofwashing (water), drying (MgS O.',) and concentration to afford a residuewhich by distillation yielded 0.160 g of aproduct of b.p. ca. 80/0.01Torr containing more than 50 of the desired ketone.

A pure sample was prepared by purifying it by means of vapour phasechromatography. The analytical data of this pure compound were identicalwith those of a sample separately prepared according to Helv. Chim.Acta, 53,541 (1970).

2,6,6-Trimethyl-1-hydroxy-1-[3-hydroxy-but-lynyl]-cyclohex-2-ene used asstarting material in the hereinabove described process can besynthesized as follows:

133 ml of a 1.75N solution of n-butyl-lithium in hexane (0.233 mole)were added dropwise to a stirred solution of 7.5 g of but-1-yn-3-ol(0.107 mole) in 50 ml of tetrahydrofuran at 75". The reaction mixturewas then kept at room temperature for 30 minutes, then again cooled to75. At this temperature there were rapidly added to a solution of 9.85 gof 2,6,6-trimethylcyclohex-Z-ehone [which may be prepared in accordancewith the method described in J. Am. Chem. Soc., 77, 5991 (1955)] in 25ml of tetrahydrofuran (0.071 mole). Stirring was continued'for minutesat -75, then overnight at room temperature. After concentration of themixture, water was added thereto, and the said mixture was extractedwith n-penta ne The combined extracts were thensubjected to the usualtreatments of washing 'withwater, drying overMgSO and concentration toyield aresiduewhi ch byfractionaldistillation afforded' 12.0 g of thedesired diol; b.p.

By carrying out the above process in the absence of mercuric acetate,2,6,6-trimethyl-1-[but-2-enoy1]- cyclohexa-1,3-diene is obtained at alower yield.

(4H. m); 4.54 (1 m);-

EXAMPLE 4' 2-Methylene-6,6-dimethy1-1-[ 1-hydroxy-but-2-enyl cyclohexaneA mixture of 0.97 g of 3,3-diImethyl-l-cyclohex-1- enyl-methyl-crotylether in 10 ml of diethyl ether and 1.75 ml oftetramethylethylene-diamine was stirred under nitrogen atmosphere. Thetemperature was brought to 80 and 9.4 ml of a 1.6N solution of butylvrated and the aqueous layer was extracted with two 7 portions of 25 mleach of pentane. The organic extracts were washed three times with 100ml of water and then procedure:

dried over anhydrous K CO The volatile portions were evaporated on thewater-bath through a spiralshaped column of 20 cm length and theobtained residue was distilled under reduced pressure.

' By subjecting the crude reaction product to vapour phasechromatography (061. 2.3 m, 15 CARBO- WAX, 135) or (col. 5 m, 15CARBOWAX, 140) there were isolated 30 of 2-methylene-6,6-dimethyl-1-[1-hydroxy-but-2-enyl]-cyclohexane (A) having the following constants:

IR 3460, 2860-3080, 1670, 1640, 1450, 1380, 1 160, 1120, 960, 890, 870,800, 740, 680 cm NMR(CC1.,) 0.88, 1.01 (s); 1.45, 1.66, 2.11, 4.20,4.45, 4.79, 5.46 (m) 8 ppm MS m/e: 194, 139, 124, 109,95, 8], 71,55, 41,27.

and 42 %of 6,6-dimethyl-2-[1-hydroxy-2-methyl-but-3-enyl]-cyclohex-1-ene (B), isomer (2), having the following constants:

IR 3400, 3080, 2820-3000, 1640, 1450, 1360, 1275, 1200, 1130, 970-1040,940,910, 870, 770 cm NMR (CCl 0.95 (broad s); 1.25-1.60 (m); 3 .0-

(broad s); 3.60 (broad d); 4.63-6.20 (in) 6 ppm MS: m/e: 176,139, 121,109, 95, 81,69, 55, 43, 29.

The 3,3-dimethyll-cyclohexyll-enyl-methyl-crotyl ether used as startingmaterialin the above described preparation was obtained according to thefollowing A solution of 7 g of 6,6-dimethyl-2-hydroxymethy1-cyclohex-l-ene [which can be prepared according to Helv. Chim. Acta, 34,72s (1951), or J. Am. Chem.

$00., 69, 1361 (1947)] in 30 ml of ether was cooled to To this solutionthere were added. dropwise within 10 minutes 31 m1 of a 1.6Nn-butyl-lithium solution in hexane. Stirring was continued for.5 minutesat '80 then the mixture was allowed to stand for 20 minutes at roomtemperature. It was concentrated under reduced pressure, andto theobtained viscous residue Y on a Vigreux column. 7.6 g (78 of the desiredether, b.p. l07- 1 12/12 Torr, were recovered, purity about 93 accordingto the analysis by vapour phase chromatography (col. 2.3 m, 15 CARBOWAX,150?).

NMR (CCI 0.96 (s); l.202.l0, 3.70 (m); 5.27 (broad s); 5.48 (broad t) 8ppm The rearrangement of 3,3-dir'nethy1-l-cyclohex-lenyl-methyl-crotylether described in the present example was repeated under variousconditions by following, however, the described general method. TheTable shown below sums up these conditions and the results obtained. Inthe said Tablethe following conventional signs have been used.

b.p. 50 -52/0.03 Torr 4.85 g (63 The analysis by means of a vapour phasechromatography (1.25 m; 15 CARBOWAX, 125) showed that the distillateconsisted of a mixture 3:5 of the two diastereoisomers of thedesiredproduct of formula lsomer 1:

1R 3400, 2920, 2860, 1710, 1660, 1630, 1440, 1380, 1360, 1020, 1000, 900cm NMR 0.92 (s); 1.00 (s); 1.78 (d, J=2 cps); 4.5 (m); 4.82 (m); 4.98(m) 8 ppm MS:192,149,124,123,122,121,109,107,95,93, 91, 81, 79, 77,69,67, 55, 44, 43, 41, 39. isomer 2: 7

1R similar to that of isomer 1 NMR 0.95 (s); 1.08 (s); 1.80 (d, J=2cps); 4.48 (m); 4.67 (m); 4.82 (m). 6 ppm 2-Methylene-6,6-dimethyl-1-[l-hydroxy-but-Z-ynyl cyclohexane A mixture of 7.68 g of3,'3-dimethyl-l-cyclohex-ls enyl-methyl-but-Z-ynylether (40 millimoles),40 ml of anhydrous etherand 4 ml of .te'tramethylethylenediamine wasstirred under a nitrogen atmosphere The temperature'was brought to .75'and to the mixture there were added dropwise 40 ml of a 1.7N solution ofn-butyl-lithium in hexane (68 millimoles). The mixture was maintained at75 for 2 hours and then at 30 for 2 hours, and 10 ml of water were addeddropwise. The whole was further-stirred until the temperature reachedabout.20. Theorganic layer was separated and the aqueous phase was'extract'edwith two portions of 50 ml each of pentane. The combinedorganic extracts were washed with water and then dried over MgSO andfinally the volatile'portions were removed through I a spiral-shapedcolumn under. reduced pressure. The

resulting residue was purified by fractional distillation;

E (g) amount of crotyl ether used ME (ml) organometallic reagent in Isolution in hexane or pentane S (ml) solvent used Et' sulphuric ether tp(h) reaction time THF tetrahydrofuran t (*centigrade) reactiontemperature MON dimethoxyethane n normality g C (m1) (g) catalyst nBnormal butyl-lithium TMEDA tetramethylethylenediamine s8 secondarybutyl-lithium Reaction conditions Yields of products EXPERI- E S C MEtp/t A B (l) B (2) MENT l 0.97 Et (10) TMEDA (1.7) 20 SE; 0.73 n2.75l-25 25 18 36 2 0.097 THF 1) 0.95 nB; 1.6 n 7/-25 32 25 25 3 0.097.MON (1) '0.95 nB; 1.6 n 5l-25 13.5 53 4 0.097 Et (1) 2 SE; 0.73 n 8/-259 20 34 5 0.097 THF (1) 2 SE; 0.73 n 4.5/-25 20 25 27 6 0.097 MON (1) 25B; 0 73 n 6.5/-25' 13.5 14.5 17 7 0.09.7 Et 1) 0.95.nB; 1.6 n 6.5/-25 2l 1 8 0.3 THF (4) t.BuOK (0.39) 2 n8; 1.6 n 3/-22 31 12 14.5 9 0.3 Et(4) t.BuOl('(O.39) 2 M3; 1.6 n 3l-22 28' 20 15 EXAMPLE 5 MS similar tothat of isomer 1.

The 3,3-dimethyll -cyclohexl -enyl-methyl-but-2- ynyl ether used asstarting product in the above described preparation can be obtained inaccordance with the following procedure:

a. A solution of 1.4 g of 6,6-dimethyl-2-hydroxymethyl-cyclohex-l-ene[which can be prepared according to Helv. Chim. Acta, 34, 728 (1951) orJ. Am.

ter, and dried over anhydrous magnesium sulphate.

After evaporation of the volatile portions there was obtained a residuewhich is directly used for the next reaction step.

NMR 0.95 (s); 3.76 (s); 5.45 (s, broad band) 8 ppm b. A solution of 2.76g, of but-Z-ynol (34 millimoles) in 20 ml of ether was cooled to -80".20.5 ml (35 millimoles) of a 1.65N solution of n-butyl-lithium in hexanehave been added dropwise to the above solution. The reaction mixture waskept, while stirring, for minutes at 80 and then for 20 minutes at roomtemperature. The volatile portions were evaporated under reducedpressure, and the resulting white solid residue was dissolved in ml ofdimethyl-sulphoxide. To the thus obtained solution there were added 7 g(34 millimoles) of 6,6-dimethyl cyclohex-2-enyl-methyl bromide [preparedaccording to the method indicated in the above paragraph a)]. The wholewas allowed to stand for 2 hours'at room temperature, while stirring.The organic phase was separated and the aqueous layer was extracted withpentane. The combined pentane extracts were washed with water, driedover- MgSO and concentrated by means of spiral-shaped column. Theresidue was then distilled by means of a Vigreux column. There were thusobtained 53 g of 3,3-dimethylcyclohex-1.-enyl-methyl-but2-ynyl ether (81hp. 1 l61 17/12 Torr. An analytical sample was obtained by purificationby means of vapour phase chromatography (2.3 m, 15 CARBOWAX, 140).

NMR 0.95 (s); 1.69 (t, .l=2 cps); 3.91 (s); 4.07 (q, J=2 cps); 5.50 (s,broad band) 6 ppm.

EXAMPLE 6 2-Methylene-6,6-dimethyl-1 [but-2-ynoyl]- cyclohexane 4.85 gof 2-methylene-6,6-dimethyl-1-[ l-hydroxybut-2 ynyl]-cyclohexane [whichcan be prepared according to the method described in example 5] (25millimoles) in 30 ml of a mixture of ether-hexane 1:1 were addeddropwise, while stirring, within 30 minutes to an ice-cooled solution of24 g of chromic acid (0.25N) in 24 ml of water and 15 ml of a mixture ofether-hexane 1:1. The whole was allowed to stand for 24 hours at roomtemperature, while stirring vigorously, and then diluted with water. Thereaction mixture was extracted with pentane, and the organic extracts,after the usual treatments of washing, drying and concentration, gave aresidue which, by fractional distillation under reduced pressure,yielded 3.46 g (72%) of the desired ltetone; b.p. 66-70/0.03 Torr. Ananalytical sample was purified by means of vapour phase chromatography(1.25 m. 15 CARBOWAX, 130).

1R 3080, 2915, 2860, 2810, 1655, 1435, 1380, 1360, 1320, 1230, 1160,900, 870, 835 cm- NMR 0.90 (s); 0.98 (s); 1.98 (s); 310(5); 4.75 (s,broad band); 4.85 (s, broad band) 6 ppm The obtained product can besubjected to a partial hydrogenation according to known methods in thepresence of a catalyst of the so-called Lii1d1ar type. There was thusobtained a mixture 4:1 of'cisand trans- 2-methylene6,6-dimethyllbut-2-enoyl cyclohexane, respectively.- 4

EXAMPLE 7 A base perfume composition of the Chypre type was prepared byadmixing the following ingredients (parts by weight):

in diethylphthalute By adding to 97 g of theabove base composition 3 gof 2-methylene-6,6-dimethyl- 1 but-Z-ynoyl cyclohexane there wasobtained a composition possessing by comparison with the basecomposition a better lifting as well as a natural style of spicy, headytone. Moreover, the obtained composition possessed a pleasant herbalcharacter reminiscent of laurel or myrtle. Analogous results, althoughless powerful, were achieved by adding to the base composition in thesame proportions, 2-methylene-6,6-dimethyl-1-[l-hydroxybut-l-ynyl1-cyclohexane.

EXAMPLE 8 A base perfume composition for after'shave lotion has beenprepared by admixing the following ingredients (partsby weight):

Menthol Eugenol 50 Coumarine 20 Muscone at 10 20 Phenyl ethyl alcohol 3120 Lavender oil 210 Pimento oil 40 Cinnamon oil i 5 Synth. bergamot 270Cyclopentadecanone at 10 '71 30 Methyl 2pentyl-3oxo-cyclopcntyl acetate20 Absolute oak moss l5 Benzyle salicylate 20 lsobutylsalicylate 30Geranium Bourbon oil Musk ketone 20 Ethyl alcohol 50 1000 in Z ethylalcohol By adding to 95 g of the hereinabove given based composition 5 gof 2 methyl-1-[but-2-enoyl]-cyclohex l-ene there is obtained bycomparison with the base composition a perfume composition possessing apleasant and fresh leathery note.

EXAMPLE 9 Preparation of a flavouring composition of the Tutti-Frutti"type A flavouring composition of the: Tutti-Frutti" type was prepared byadmixing the following ingredients (parts by weight):

Vanillin 20 Allyl caproate l Citral 20 Amyl butyrate 35 Orange O1] 45Ethyl butyrate 75 Ethyl acetate 185 Amy] acetate 185 Lemon oil 400 Total975 25 g of 2-methyl-l-[but-2-enoyl]-cyclohex-l-ene were added to 975 gof the above mixture called test composition. A check composition wasprepared by the addition of 25 g of lemon oil to 975 g of the abovemixture.

' The test and check compositions were added to the foodstuffs describedbelow in the indicated proportions (100 kg of product to be flavoured):

Cake 20 g Custard 5 g Candy g Candy: 100 ml of sugar syrup (obtained bydissolving one kilogram of sucrose in 600 ml of water) and 20 g ofglucose were mixed and slowly heated to 145. The flavour was added tothe mass and the mixture was allowed to cool and harden.

Custard: A mixture of 60 g of sucrose and 3 g of pectin were added,while stirring, to 500 ml of warm milk. The mixture was brought to theboiling point for a few seconds and the flavour was added, whereupon thewhole was cooled.

Cake: The following ingredients were mixed: 100 g of vegetablemargarine, 1.5 g of NaCl, g of sucrose, 2 eggs and 100 g of flour. Theflavour was added to the above mass and the whole was heated to for 40minutes. r

The samples of finished foodstuff were tasted by a group of experts whohad to state their opinion as to the taste of the samples which had beensubmitted to them. All the members of the group declared that the testsamples had a more marked fruity note than that of the check samples andthat they moreover possessed a character which was reminiscent of redberries. Moreover, the test samples possessed a character reminiscent ofdried fruit.

When 2-methylene-6,6-dimethyll but-2-ynoyl]- cyclohexane was addedinstead to the base composition, the effects achieved on the flavouredfoodstuffs were analogous; the flavouring character was, however, morefruity, reminiscent of peach or apricot.

We claim:

1. A compound ofthe formula wherein R and R represent lower alkylradicals con- UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTIONPatent No. 3,852,355 Dated December 3, 1974 Inventor(s) ValentinRautenstrauch and Ferdinand Naf It is certified that error appears inthe above-identified patent and that said Letters Patent are herebycorrected as shown below:

Column 10', Line 24, "15" should read -15% Column 12 Line 2, "a vapour"should read --vapour-- Column 14, Line 2, "10%" should read --lO%*-Signed and sealed this huh day of February 1975.

(SEAL) Attest:

McCOY M. GIBSON JR. C. MARSHALL DANN Attesting Officer Commissioner ofPatents

1. A COMPOUND OF THE FORMULA 2.2-Methylene-6,6-dimethyl-1-(but-2-ynoyl)-cyclohexane.